Exclusive 'Mortal Instruments: City Of Bones' Trailer: Watch Now!

Lily Collins and Jamie Campbell Bower star in big-screen adaptation of Cassandra Clare's best-selling novel.

There is a world hidden within our own, unseen by Mundane eyes. But come August 23, 2013, all will be revealed when the supernatural romance "The Mortal Instruments: City of Bones" hits theaters.

Based on the best-selling young-adult novel by Cassandra Clare, "City of Bones" follows seemingly average teen Clary Fray (played by Lily Collins), whom upon her mother's disappearance is plunged into the secret universe of the Shadowhunters — a half-human, half-angel race tasked with protecting the world from dangerous demons.

Clary's ally within this society is the impossibly beautiful, yet incredibly snarky, Jace Wayland (played by Jamie Campbell Bower). It's in Pandemonium night club that the two improbably meet in the opening moments of the trailer — improbable because Jace has used his Shadowhunter powers to make himself invisible to Mundanes (i.e. humans). But Clary does see him, hinting there is more to her than meets the eye.

Set to John Murphy's epic "Kaneda's Death, Pt. 1," the first look hurdles through Clary's introduction to this brave new world and her fight to find her mother, as vampires, demons and all manner of frightening foes stand in her way.

Click play on the trailer above to watch the entire "City of Bones" teaser trailer, and be sure to stick around after the clip, because the following video features an expert commentary from none other than author Cassandra Clare.

Co-starring Jonathan Rhys Meyers, Jared Harris and Lena Headey, and directed by Harald Zwart, "The Mortal Instruments: City of Bones," hits theaters August 23, 2013.

Check out everything we've got on "The Mortal Instruments: City of Bones."